It seemd to be working fine on my mark 2, but then I started getting the spontaneous reboots. Also sometimes the player seems to still be responding to commands, it will just stop playing music.

Now that's very interesting, especially the audio deadlock while still responding to commands. By that do you mean that menus etc. still worked? If you try to play something from the menus, does it play, or stay stuck at 0:00? Was there any specific thing you could do to provoke it?

Peter